The proposal by the American Federation of Teachers calls for a nationwide, standardized test that would be administered by state-level unions, similar to the way states host bar exams for lawyers.

Union President Randi Weingarten said the proposed competency test is largely in response to young public-school teachers expressing concerns about being unprepared to enter a classroom.

“It’s not fair to students, and it’s not fair to teachers if they are not prepared on Day One,” she said.

Teachers unions have recently faced increased criticism, particularly from Republican governors, allegedly for demanding high teacher salaries without providing their states with affordable and quality educations.

Though poor-performing tenured teachers are among the biggest concerns, because they are difficult if not impossible to fire, the union proposal does not address that issue.

New Jersey Republican Gov. Chris Christie came down especially hard last year on the state’s teachers union, saying its refusal to negotiate on a salary freeze resulted in layoffs and larger classrooms.

"I believe the teachers in New Jersey in the main are wonderful public servants that care deeply,” he told ABC News. “But their union (is) a group of political thugs."

Christie has also suggested big changes to New Jersey’s tenure program, including yearly reviews for those teachers and the ability to remove the under-performers.

Weingarten said Monday that unions help tenured teachers improve through professional development and evaluations.

“What we’re focusing on is preparing new teachers,” she said in response to a question from FoxNews.com in a conference call.

A union task force came up with the test, which its board of directors still must approve before asking states to adopt the concept.

The task force also calls for teachers and educators to set and enforce the standards and said the National Board for Professional Teaching Standards has agreed to get all parties together to design the standards.

To pass the written exam, teachers would also need a minimum grade point average and at least one year of successful student teaching.

Education Secretary Arne Duncan is commending the proposal. He says the U.S. shouldn't tolerate having unprepared teachers.

"It's time to do away with a common rite of passage into the teaching profession -- whereby newly minted teachers are tossed the keys to their classrooms, expected to figure things out and left to see if they and their students sink or swim,” Weingarten said.